The present invention relates to an above ground liquid waste storage tank and more particularly to an above ground waste storage tank having improved capability to store flammable and combustible liquids.
In my patent application Ser. No. 07/294,717 for "Underground Storage Tank" filed on Jan. 9, 1989, I disclose and claim an underground storage tank for chemicals constructed out of fiberglass. In many situations it is necessary to store such chemicals in tanks which are above ground. Tanks which are designed for use underground are not normally suitable for use in a more exposed environment.
Typical above ground waste storage tanks for flammable and combustible liquids are made out of steel and are subject to problems of corrosion which limit their useful life, especially when they are being used to contain dangerous fluids. In addition, in the event of a fire outside the tank, the steel being an excellent conductor of heat rapidly transfers the heat into the liquid contained therein, thus increasing the hazard of spreading the fire. Other problems associated with steel tanks have to do with problems of moisture condensing out on the inside of the tank, the danger of sparks igniting the fluid contained in the tank, and the weight of the tank requiring a concrete foundation for its support.
Tanks which are made out of fiberglass generally tend to adhere to existing designs, merely substituting fiberglass for the steel. Such tanks are unable to meet the one hour fire code rating, which will be described below.